Cutting-ring assembly

Abstract

A cutting-ring assembly configured for use in a tunnel boring machine includes a cutting ring, an axle, and a bearing unit. The cutting ring is rotatably supported on the axle via the bearing unit, and the bearing unit includes at least one rotating outer ring having a first raceway and a second raceway, at least one fixed inner ring having a first raceway and a second raceway, and rolling elements between the raceways. Either the at least one inner ring or the at least one outer ring includes a first ring having an elongated axially extending shoulder and a second ring having an elongated axially extending shoulder abutting against the elongated axially extending shoulder of the first ring.

What is claimed is: 
     
       1. A cutting-ring assembly configured for use in a tunnel boring machine, comprising:
 a housing including a housing ring with opposing external axial ends, 
 a cutting ring attached to the housing, 
 an axle, and 
 a bearing unit disposed within the housing, 
 wherein the housing and the cutting ring are rotatably supported on the axle via the bearing unit, 
 wherein the bearing unit includes at least one rotating outer ring having a first raceway and a second raceway, at least one fixed inner ring having a first raceway and a second raceway, a first row of rolling elements between the first raceway of the at least one outer ring and the first raceway of the at least one inner ring and a second row of rolling elements between the second raceway of the at least one outer ring and the second raceway of the at least one inner ring, and 
 wherein: 
 the at least one inner ring comprises a first inner ring having an elongated axially extending shoulder and a second inner ring having an elongated axially extending shoulder abutting against the elongated axially extending shoulder of the first inner ring such that the spacing of the first and second rows of rolling-elements is defined by the elongated shoulder of the first ring and the elongated shoulder of the second ring, and 
 the housing includes a closure cap having an outer radial portion, the outer radial portion being disposed against one of the external axial ends of the housing ring so as to be located externally of the housing ring, and an inner radial portion disposed at least partially within the housing ring and against the first inner ring and a nut secures the housing about the axle, the nut engaging against the closure cap such that a preload force is exerted on the first inner ring, through the first row of rolling elements, the at least one outer ring, the second row of rolling elements, and the second inner ring and back to the first inner ring through the abutting shoulders of the first inner ring and the second inner ring. 
 
     
     
       2. The cutting-ring assembly according to  claim 1 ,
 wherein the rolling elements comprise tapered rollers. 
 
     
     
       3. The cutting-ring assembly according to  claim 1 ,
 wherein the axially extending shoulders are integrally formed. 
 
     
     
       4. The cutting-ring assembly according to  claim 1 ,
 wherein the bearing unit is configured as a preinstalled bearing unit mounted in the housing, and 
 wherein the cutting ring is releasably attached to the housing. 
 
     
     
       5. The cutting-ring assembly according to  claim 4 ,
 wherein the end cap and/or the closure cap is configured to seal the housing. 
 
     
     
       6. The cutting-ring assembly according to  claim 5 ,
 wherein a dynamic seal is provided between the end cap and the housing ring, and/or between the housing ring and the closure cap. 
 
     
     
       7. The cutting-ring assembly according to  claim 1 ,
 wherein the bearing unit includes a first seal assembly and a second seal assembly each configured to seal an interior of the bearing unit, and 
 wherein the first seal assembly is disposed on an axial outer side of the bearing unit between the inner ring and the outer ring. 
 
     
     
       8. The cutting-ring assembly according to  claim 7 ,
 wherein the bearing unit is configured as a preinstalled bearing unit mounted in a housing, and 
 wherein the first seal assembly and the second seal assembly are each part of the preinstalled bearing unit and each is configured as a cassette seal. 
 
     
     
       9. The cutting-ring assembly according to  claim 1 , wherein
 the at least one outer ring comprises a one-part outer ring. 
 
     
     
       10. A tunnel boring machine that includes at least one cutting-ring assembly according to  claim 1 . 
     
     
       11. The cutting-ring assembly according to  claim 1 , wherein the at least one outer ring includes a single outer ring disposed within the housing or two abutting outer rings disposed within the housing such that the preload force is transferred directly from the first row of rolling elements to the single outer ring or to the two abutting outer rings and then directly to the second row of rolling elements. 
     
     
       12. A cutting-ring assembly configured for use in a tunnel boring machine, comprising:
 a housing, 
 a cutting ring attached to the housing, 
 an axle, and 
 a bearing unit disposed within the housing, 
 wherein the housing and the cutting ring are rotatably supported on the axle via the bearing unit, 
 wherein the bearing unit includes at least one rotating outer ring having a first raceway and a second raceway, a first fixed inner ring having a first raceway and a second fixed inner ring having a second raceway, a first row of rolling elements between the first raceway of the at least one outer ring and the first raceway of the first inner ring and a second row of rolling elements between the second raceway of the at least one outer ring and the second raceway of the second inner ring, 
 wherein the first inner ring includes a first elongated axially extending shoulder and the second inner ring includes a second elongated axially extending shoulder abutting against the first shoulder, and 
 wherein the bearing unit is configured as a preinstalled bearing unit mounted in the housing, the cutting ring being releasably attached to the housing, the housing including a housing ring having two external axial ends, an end cap and a closure cap, the end cap being disposed against one external axial end of the housing ring and configured to seal the housing and/or the closure cap being disposed against the other external axial end and configured to seal the housing, and at least one dynamic seal device including a one-piece seal ring having one axial end disposed within the housing ring axially external to the end cap or the closure cap and another axial end disposed within the end cap or the closure cap axially external to the housing ring. 
 
     
     
       13. The cutting-ring assembly according to  claim 12 ,
 wherein the rolling elements of the first row of rolling elements comprise tapered rollers and the rolling elements of the second row of rolling elements comprise tapered rollers. 
 
     
     
       14. The cutting-ring assembly according to  claim 13 ,
 wherein the at least one outer ring comprises no more than one outer ring. 
 
     
     
       15. The cutting-ring assembly according to  claim 13 ,
 wherein the first fixed inner ring includes a body portion including the first raceway of the first fixed inner ring and wherein the first elongated axially extending shoulder is formed integrally with the body portion of the first fixed inner ring, and 
 wherein the second fixed inner ring includes a body portion including the second raceway of the second fixed inner ring and wherein the second elongated axially extending shoulder is formed integrally with the body portion of the second fixed inner ring. 
 
     
     
       16. A tunnel boring machine that includes at least one cutting-ring assembly according to  claim 13 .